Arterial stenosis is one of the most serious forms of arterial disease. In clinical practice, stenosis severity is estimated by using either simple geometrical parameters, such as determining the percent diameter of a stenosis, or by measuring hemodynamically based parameters, such as the pressure-based myocardial Fractional Flow Reserve (FFR). FFR is an invasive measurement of the functional significance of coronary stenoses. The FFR measurement represents a ratio between maximal blood flow in an area of stenosis and maximal blood flow in the same area without the stenosis. Earlier studies have shown that lesions with an FFR that is less than 0.75 provide an accurate predictor of ischemia; and that deferral of percutaneous coronary intervention for lesions with FFR≥0.75 appeared to be safe.
Modeling vascular flow to assess vascular flow is described, for example, in U.S. published patent application number 2012/0059246 of Taylor, to a “Method And System For Patient-Specific Modeling Of Blood Flow”, which describes embodiments which include a system for determining cardiovascular information for a patient. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of at least a portion of an anatomical structure of the patient. The portion of the anatomical structure may include at least a portion of the patient's aorta and at least a portion of a plurality of coronary arteries emanating from the portion of the aorta. The at least one computer system may also be configured to create a three-dimensional model representing the portion of the anatomical structure based on the patient-specific data, create a physics-based model relating to a blood flow characteristic within the portion of the anatomical structure, and determine a fractional flow reserve within the portion of the anatomical structure based on the three-dimensional model and the physics-based model.
Additional background art includes: U.S. Pat. No. 8,548,778 of Taylor.
Further background art includes U.S. Patent Publication No. 2015/0342551 to Lavi et al.; International Patent Publication No. WO2015/059706 to Lavi et al.; U.S. Patent Publication No. 2015/0335304 to Ifat Lavi et al.; U.S. Patent Publication No. 2015/0339847 to Benlshti et al.; and U.S. Patent Publication No. 2015/0265162 to Lavi et al.; the contents of which are hereby incorporated herein by reference.